Effect of Nd addition on the microstructure and mechanical properties of extruded Mg-Gd-Zr alloy

Herein, the microstructure and mechanical properties of newly developed Mg-4Gd-0.5Zr-xNd (x = 0, 0.5, 1 and 1.5 wt%) extruded alloys are investigated systematically. All the extruded alloys exhibit the complete dynamically recrystallized (DRXed) microstructure. The addition of Nd weakens the texture and decreases the intensity of double peak texture apparently from 13.08 to 8.78 m.r.d (at 1.5 wt%). With increasing the Nd content from 0 to 1.5 wt%, the grain sizes of Mg-4Gd-0.5Zr alloys gradually decrease from 11.02 to 7.90 mu m, accompanying with massive fine dispersed Mg41Nd5 and Mg12(Nd,Gd) particles in the matrix. In terms of mechanical properties, the yield strength increases substantially without the loss of elongation-to-failure basically as increasing the Nd content from 0 to 1.5 wt%. Of those, the Mg-4Gd-0.5Zr-1.5Nd alloy possesses the highest yield strength (160.2 MPa), which is 82.3% higher than that of Mg-4Gd-0.5Zr alloy (87.9 MPa). Meanwhile, the Mg-4Gd-0.5Zr-1.5Nd alloy presents an outstanding ductility (39.3%).